Lag-screw expansion-shield



J. E. OGDEN. LAG SCREW EXPANSION SHIELD. APPLICATION FILED sums, I919.

Patented Dem-13,1921.

PATENT OFFICE.

JOHN EDWARD OGDEN, OF MOUNTAINVILLE, NEW YORK.

LAG-SCREW EXPANSION-SHIELD.

Specification of Letters Patent.

Patented Dec. 13, 1921.

Application filed September 5, 1919. Serial No. 321,740.

To all whom it may concern:

Be it known that 1, JOHN EDWARD OGDEN, a citizen of the United States ofAmerica, and a resident of Mountainville, town of Cornwall, Orangecounty, and State of New York, have invented certain new and usefulImprovements in Lag-Screw Expansion- Shields, of which the following isa specification, reference being had to the accompanying drawings,forming a part thereof.

This invention relates to improvements in expansion shields which may beused to secure lag screws and the like in walls of material with whichthe threads of the screws cannot engage firmly, by being expanded by theinsertion of the screws into engagement with surfaces of holes in whichthe shields are inserted. These shields are longitudinally divided atleast throughout the greater part of their length or else are made oftwo or more longitudinally divided sections which are laterallyseparated when, a screw is forced between them. The specific object ofthe invention is to decrease the cost of,

manufacturing by providing a simple structure which may be constructedof stamped metal. Another object. is to so form the parts that theexpansion occurs in the plane of division instead of at right anglesthereto, and to so corrugate the metal as to form screw threads whichform a bore which tapers in the plane of division.

These and other objects of the invention will appear in the followingspecification in which I will describe the invention, the novel featuresof which will be set forth in appended claims.

Referring to the drawings:

Figure 1 is a sectional elevation of an expansion shield which is madeaccording to and embodies this inventiomthe section bein taken on theline 1-1 of Fig. 2.

*ig. 2 is a bottom plan'view of the device shownin Fig. 1.

Fig. 3 is a sectional elevationof another form of expansion shield whichalso embodies this invention, the section being taken on the line 33 ofFig. 4.

Fi a 4 is a bottom plan view of the shield show n in Fig. 3..

Fig. 5 is a sectional elevation of a shield of another modified form ofconstruction, the section being taken on the line 5-1-5 of F i ff Fig. 6is a bottom plan or end view of the form of shield shown in Fig. 5.

Fig. 7 is a sectional elevation taken at right angles to the section ofFig. 5 or on the line 77 of Fig. 6. e

Fig. 8 is a top plan view of the shield shown in Figs. 5-7.

Like characters of reference designate corresponding parts in allthedrawings.

10 designates a tubular shell of stamped or pressed metal ofsubstantially uniform thickness, either divided longitudinallythroughout the greater part of its length along lines which arepreferably in the same plane, or else constructed of two or more partsand therefore divided longitudinally throughout the length of thedevice. In either case the dividing lines are those designated by 11 and12 in Fig. 2. The outermost parts of this shield lie in a commoncylindrical imaginary surface.

The walls of this shell are formed into longitudinal corrugations 13which increase in height slightly from the outer to the innor end of theshell and other corrugations 1-4 which increase in height to a greaterdegree. 'The result is that while the inner part or bore of the shelltapers slightly in the planes of the corrugations 13, it tapers to agreater extent on the plane of the dividing lines 11 and 12 so thatthe'inner end thereof forms an ellipse with its major axis at rightangles to the plane of division.

The parts of the shell between the longitudinal corrugations 13, 13 and14 are helically corrugated as at 15 to form threads with which those ofa lag screw or similar device may engage, the threads so formedgradually increasing in height from the outerto the inner end of theshield, those on the corrugations 14 attaining a greater height thanthose on the other corrugations. At this point it may be remarked thatwhile I have shown the shield as divided on lines 11, 12 passing,through the larger corrugations 14, it is to be distinctly understoodthat such arrangement is not to be taken as alimitation of the inventionfor the same may be successfully practised bydividing the shell throughthe corrugations 13. It will now be observed that the corrugations (13,14), radually "increase in height in planes passing through the axis ofthe shell and v simila ly n rease in width. in p n s at right anglesthereto. It may be seen that when this device is inserted in a holewhich it approximately fits, and a lag screw is screwed lnto it,expansion will occur radially along the lines 11 and 12. The metal iscomparatively rigid and its stiffness is increased by the'corrugations.The result is that the aforesaid expansion causes the shield to be whatsimilar in construction and operation.

It comprises a substantially cylindrical shell 20with its lines ofdivision designated by 21, 22. The longitudinal corrugations in thiscase extend inwardly from the body proper instead of outwardly as in theformer case and are designated respectively by 23 and 24, thosedesignated by 24k tapering .to a greater extent than the others. Theribs thus-formed are also helically corrugated as at 25 to form screwthreads. Y

A still further and perhaps preferred form of construction is shown inthe remaining figures of the drawings. In these figures the shell isdesignated by 30 divided on the plane of lines 81, 32. Near its outerend are some outwardly extending longitudinal corrugation 33, beyondwhich is an annular groove 34E for the reception of a ring 35 of springwire which serves to hold the parts of theshell together. The rest ofthe body of the shell is corrugated helically to form screw threadswhich in the plane of the line 7-7, (Fig. 6), orrin other words alongthe major axis of the ellipse, are of uniform height as shown in Fig. 7,but which in the plane of the lines of division 31 and 32 progressivelyincrease in height toward the in ner end of the shield as shown in Fig.5. The shield is further strengthened and stiffened by having the edgesadjacent the lines of separation turned outwardly to form longitudinalribs 36. In either case the screw threads themselves may be of uniformheight throughout the length of threaded part of the device, so long asthe shield is so formed that the maximum taper of the threaded bore isin the plane of the line of division.

I have illustrated and described a number of forms of construction ofexpansion shields which embody this invention in order to show that I donot intend to limit myself to any particular form of construction and infact I intend no limitations other thanthose imposed by. the appendedclaims.

V .What I claim 1s:

1. An expansion shield comprising a tubular body formingexpansion'members divided from each jotheratleast a part of the lengthofthe body, the walls of said body being. corrugated to form screwthreads, the outside of which corrugations lie substantially in acylindrical surface, said corrugations 1 progressively increasing inheight in a given axial plane toward the inner end of the body to agreater extent than'in similar planes angularly adjacent said given plan2. An expansion shield comprising a tubular body forming expansionmembers divided from each other in one plane at least a part of thelength of the body, the walls of said body being corrugated to formscrew threads, the outside of which corrugations lie substantially in acylindrical surface, said corrugations progressively increasing inheight inthe plane of division toward the inner end of the body to agreater ex tent than in planes removed from said plane.

3. An expansion shield comprising a tubular body'forming expansionmembers divided from each other at least a part of the length of thebody, the walls of said body being'corrugated, the outside of whichcorrugations lie substantially in a cylindrical surface, saidcorrugations progressively increasing in height in the planes ofdivision toward the inner end of the body to a greater extent than inother planes. i

4. An expansion shield comprising a tubular body forming expansionmembers divided from each other at least a part of the length of thebody, the walls of said body being corrugated to form screw threads, theouter parts of said body lyingsubstantially in a cylindrical surface andsaid corrugations forming a threaded bore which tapers in the plane orplanes of the lines of division to a greater extent than in otherplanes. 7

5. An expansion shield comprising a tu bular body forming expansionmembers di-' vided from each other at least a part of the length of thebody, the walls of said body being provided with a plurality ofcorrugations the outside of which lie substantially in a cylindricalsurface, thecorrugations at the plane of division increasing in heighttoward the inner end of the body, and the corrugations away from theplane of division increasing in a similar manner but to j a lesserdegree.

6. An expansion shield comprising a tubular body forming expansionmembers divided from each other in one plane at least a part of thelength of the body, said body having near on of its ends longitudinalcorrugations forming outwardly projecting ribs, and being helicallycorrugated through out another portion of its length to form screwthreads progressively increasing. in height in the plane of divisionof-the memhere to a greater extent than in other planes, and the outsideof said helical corrugations lying substantially in a cylindricalsurface.

An expansion shield comprising similar members divided from each otherin one plane, said shield having near one 'of its ends longitudinalcorrugations forming outwardly projecting ribs and an annular groove,and being helically corrugated throughout another portion of its length.to form screw threads progressively increasing in height in the plane ofdivision of the members to a greater extent than in other planes, theoutside of said helical corrugations lying substantially in acylindrical surface, and a holding means in the annular groove.

8. An expansion shield comprising a tubular body divided longitudinallyfor at least a portion of the length of the same to provide two or moreexpansion members and provided with longitudinal corrugations in theplane of such division, said body being further corrugated to form screwthreads gradually increasing in height in said plane of division.

9. An expansion shield comprising a tubular body divided for at least aportion of its length to form a plurality of expansion members, andprovided with longitudinally extending ribs helically corrugated intoscrew threads increasing in height longitudinally of the shield.

10. An expansion shield comprising a tubular body divided for at least aportion of its length to form a plurality of expansion members, andprovided with longitudinally extending ribs helically corrugated intoscrew threads increasing in height longitudinally of the shield, thehelical corrugations in the ribs nearest the lines of divisionincreasing in height to a greater extent than the others.

11.. 'An expansion shield comprising a tubular body divided for at leasta portion of its length into a plurality of expansion members andprovided with longitudinally extending corrugations forming a pluralityof ridges which lie in the surfaces of a plurality of imaginary cones ofrelatively different angularity.

12. An expansion shield comprising a tubular body, the walls of whichare corrugated to form screw threads with the outside of thecorrugationslying substantially in a cylindrical surface, said corrugationsprogressively increasing in height in a given axial plane from one endtoward the opposite end of the body and said body further havinglongitudinal corrugations intercepting the screw thread corrugationsaforesaid.

In witness whereof I hereunto set my hand this 21st day of August, 1919.

JOHN EDWARD OGDEN.

Witness I. B. Moons.

